1. Field of the Invention
The present invention relates to a battery control device and to an electricity storage device.
2. Description of Related Art
In an electric automobile or a hybrid type automobile, a battery module is used in which a plurality of assembled batteries, in each of which a plurality of secondary cells (unit cells) such as lithium cells or the like are connected in series or in series-parallel, are themselves connected in series or in series-parallel. Furthermore, an assembly of a plurality of these battery modules connected in series or in series-parallel, together with a battery control circuit that controls these battery modules, is used as an electricity storage device.
When a large number of secondary cells are connected in series and a control device for detecting the voltages of these cells is connected thereto, precautions are required in order for high current not to flow to the control device and for high voltage not to be applied to its internal integrated circuits, since this would cause them to be damaged or to fail. For example in Japanese Laid-Open Patent Publication 2007-280872, when a battery pack (i.e. an battery assembly) in which a plurality of secondary cells are connected in series-parallel is to be connected to a control device, a special type of connector is used in which the lengths of the connector pins vary, so that the voltage detection lines are connected in order from the low potential side of battery voltage within the battery pack.